Research Article ...downloads.hindawi.com/archive/2011/589073.pdf · 4Department of Physics, PSG...
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International Scholarly Research Network ISRN Nanotechnology Volume 2011, Article ID 589073, 4 pages doi:10.5402/2011/589073 Research Article Synthesis and Characterization of Selenium Nanowires C. K. Senthil kumaran, 1 S. Agilan, 1 Dhayalan Velauthapillai, 2 N. Muthukumarasamy, 1 M. Thambidurai, 1 T. S. Senthil, 3 and R. Balasundaraprabhu 4 1 Department of Physics, Coimbatore Institute of Technology, Coimbatore 641014, India 2 Department of Engineering, University College of Bergen, 5020 Bergen, Norway 3 Department of Physics, Erode Sengunthar Engineering College, Erode 638057, India 4 Department of Physics, PSG College of Technology, Coimbatore 641004, India Correspondence should be addressed to C. K. Senthil kumaran, ck [email protected] Received 11 April 2011; Accepted 24 May 2011 Academic Editors: J. M. Calder ´ on-Moreno, C.-L. Hsu, and D. Nesheva Copyright © 2011 C. K. Senthil kumaran et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Selenium nanowires have been grown by chemical method. The effect of annealing on the properties of the prepared selenium nanowires has been studied. The X-ray diffraction studies indicated the formation of selenium with trigonal phase, and no secondary phase was observed. The composition analysis results show that selenium is present in the sample. HRTEM images reveal that selenium nanowires have diameter ranging from 30–50 nm and length of 1-2 μm. The diameter and length of nanowires have been found to increase with increase in annealing temperature. 1. Introduction One-dimensional (1D) nanostructural materials such as nanotubes, nanowires, and nanorods have recently received much attention due to their interesting properties and are potential candidates for application in different fields. The one-dimensional nanostructured selenium nanowires have been widely studied because of their functional properties in superconductivity [1], high photoconductivity, and catalytic activity. Selenium nanowires find application in the areas of photoelectric cells, xerography, light-measuring devices, and solar batteries [2]. Fan et al. [3] have synthesized Se microrods, microtubes, and dendrite type microstructure by using Se powder and NaOH as starting materials under hydrothermal condition. t-Se in the form of nanowires and nanoribbons or nanobelts have been synthesized using β- carotene [4] and cellulose [5] as reducing agent by same method at 160 ◦ C. Zhang et al. have prepared t-Se nanowire arrays by electrodeposition using anodic porous alumina templates [6]. Li and Yam’s group has employed ascorbic acid as the reducing agent under the assistance of β-cyclodextrin to make selenium nanowires [7]. Chen et al. have prepared t-Se nanorods through a hydrothermal route [8]. Selenium has a high reactivity towards a variety of chemicals, which can be explored to transform selenium element into many other important functional materials, such as PbSe, ZnSe, and CdSe [9–11]. Selenium is extensively known as an important elemental semiconductor as well as an essential element in biology and chemistry. Selenium is also one of the essential trace elements for human beings. It has been confirmed that selenium can improve the activity of the selenoenzyme, gluthione peroxidase and prevent free radicals from damaging cells and tissues in vivo. Se nanomaterials have been prepared by different workers using various techniques such as hydrothermal route, chemical vapor deposition, sonochemical approaches, refluxing processes, and cellulose-directed growth [12–15]. The size and shape of nanomaterials have a major influ- ence on their physical and chemical properties, and the abil- ity to control these parameters remains a great technological challenge with important implications for nanoscale science. Special attention has been directed towards the control of size and morphology of chalcogenide nanostructures. Recently, synthesis of nanowires with controlled alignment, size, shape, and compositions based on one-dimensional structure has triggered great interest due to the fact that
Transcript of Research Article ...downloads.hindawi.com/archive/2011/589073.pdf · 4Department of Physics, PSG...
International Scholarly Research NetworkISRN NanotechnologyVolume 2011, Article ID 589073, 4 pagesdoi:10.5402/2011/589073
Research Article
Synthesis and Characterization of Selenium Nanowires
C. K. Senthil kumaran,1 S. Agilan,1 Dhayalan Velauthapillai,2 N. Muthukumarasamy,1
M. Thambidurai,1 T. S. Senthil,3 and R. Balasundaraprabhu4
1 Department of Physics, Coimbatore Institute of Technology, Coimbatore 641014, India2 Department of Engineering, University College of Bergen, 5020 Bergen, Norway3 Department of Physics, Erode Sengunthar Engineering College, Erode 638057, India4 Department of Physics, PSG College of Technology, Coimbatore 641004, India
Correspondence should be addressed to C. K. Senthil kumaran, ck [email protected]
Received 11 April 2011; Accepted 24 May 2011
Academic Editors: J. M. Calderon-Moreno, C.-L. Hsu, and D. Nesheva
Copyright © 2011 C. K. Senthil kumaran et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.
Selenium nanowires have been grown by chemical method. The effect of annealing on the properties of the prepared seleniumnanowires has been studied. The X-ray diffraction studies indicated the formation of selenium with trigonal phase, and nosecondary phase was observed. The composition analysis results show that selenium is present in the sample. HRTEM imagesreveal that selenium nanowires have diameter ranging from 30–50 nm and length of 1-2 μm. The diameter and length of nanowireshave been found to increase with increase in annealing temperature.
1. Introduction
One-dimensional (1D) nanostructural materials such asnanotubes, nanowires, and nanorods have recently receivedmuch attention due to their interesting properties and arepotential candidates for application in different fields. Theone-dimensional nanostructured selenium nanowires havebeen widely studied because of their functional properties insuperconductivity [1], high photoconductivity, and catalyticactivity. Selenium nanowires find application in the areasof photoelectric cells, xerography, light-measuring devices,and solar batteries [2]. Fan et al. [3] have synthesized Semicrorods, microtubes, and dendrite type microstructureby using Se powder and NaOH as starting materials underhydrothermal condition. t-Se in the form of nanowires andnanoribbons or nanobelts have been synthesized using β-carotene [4] and cellulose [5] as reducing agent by samemethod at 160◦C. Zhang et al. have prepared t-Se nanowirearrays by electrodeposition using anodic porous aluminatemplates [6]. Li and Yam’s group has employed ascorbic acidas the reducing agent under the assistance of β-cyclodextrinto make selenium nanowires [7]. Chen et al. have preparedt-Se nanorods through a hydrothermal route [8]. Selenium
has a high reactivity towards a variety of chemicals, whichcan be explored to transform selenium element into manyother important functional materials, such as PbSe, ZnSe,and CdSe [9–11]. Selenium is extensively known as animportant elemental semiconductor as well as an essentialelement in biology and chemistry. Selenium is also one ofthe essential trace elements for human beings. It has beenconfirmed that selenium can improve the activity of theselenoenzyme, gluthione peroxidase and prevent free radicalsfrom damaging cells and tissues in vivo. Se nanomaterialshave been prepared by different workers using varioustechniques such as hydrothermal route, chemical vapordeposition, sonochemical approaches, refluxing processes,and cellulose-directed growth [12–15].
The size and shape of nanomaterials have a major influ-ence on their physical and chemical properties, and the abil-ity to control these parameters remains a great technologicalchallenge with important implications for nanoscale science.Special attention has been directed towards the controlof size and morphology of chalcogenide nanostructures.Recently, synthesis of nanowires with controlled alignment,size, shape, and compositions based on one-dimensionalstructure has triggered great interest due to the fact that
2 ISRN Nanotechnology
10 20 30 40 50 60 70
(101
)
(100
)
Inte
nsi
ty(a
.u.)
(102
)(1
10)
(111
)
(003
)
(201
)
(103
)
(210
)
(113
)80
(c)
(b)(a)
2θ (degrees)
Figure 1: X-ray diffraction pattern of Se (a) as prepared, (b) 100◦C,and (c) 200◦C annealed samples.
these nanowires may provide opportunities to exploit newphenomena and novel properties. A large number of workabout the preparation of nanowire structures have beenreported. Notable examples including the nanowires of Sevia a chemical precipitation method [16], Se nanowires by ahydrothermal technique [17] have also been reported. Thesemethods, however, have several major drawbacks, includingthe use of toxic chemicals, extreme synthesis conditionsinvolving high-operating temperatures and/or pressures, andhighly acidic or alkaline reaction conditions. The methodused in the present study is simple and is of low cost andscale-up route and less toxic precursors and solvents havebeen used. In this paper, we report about the preparationand characterization of selenium nanowires using chemicalmethod.
2. Experimental
Selenium nanowires have been prepared using the requiredprecursors by chemical method. An aqueous solution of0.05 M of SeO2 and starch (50 mg) were dissolved in waterand stirred for about one hour at room temperature.Ascorbic acid (0.025 M) was added dropwise to the abovementioned solution. The colour of the solution changed intobrick-red, indicating the formation of Se nanoparticles inthe solution. The solution was stirred for 5 hours at roomtemperature. After 5 hours, the suspension was centrifugedand washed with water and ethanol several times. Thesamples were then suspended in ethanol and allowed toage for 2 hours without stirring. After centrifugation, thesamples were dried at room temperature. The Se sampleshave been annealed at 100◦C and 200◦C for 1 h using aheating rate of 2◦C/min.
X-ray diffraction studies have been carried out usingPANalytical X-ray diffractometer, and surface morphologyof the samples has been studied using scanning electronmicroscope (JEOL JSMS 800-V). Transmission electron
1 μm
(a)
1 μm
(b)
1 μm
(c)
Figure 2: SEM image of Se (a) as prepared, (b) 100◦C annealed, and(c) 200◦C annealed.
microscope (HRTEM) images of the prepared Se have beenrecorded using a JEOL JEM2100 microscope. Compositionalanalysis of the samples has been studied using energydispersive analysis of X-rays (JEOL Model JED-2300).
3. Results and Discussion
Figure 1(a) shows the X-ray diffraction patterns of as pre-pared Se. The diffraction peaks at 2θ (degrees) of 23.57◦,29.73◦, 41.28◦, 43.68◦, 45.43◦, 51.72◦, 56.07◦, 61.62◦, 65.24◦
and 71.60◦ are, respectively, indexed as the (100), (101),(110), (102), (111), (201), (112), (103), (210), and (113)planes of Se. All the diffraction peaks in the 2θ range
ISRN Nanotechnology 3
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900
800
700
600
500
400
300
200
100
00 1 2 3 4 5 6 7 8 9 10
Cou
nts
(keV)
eds
SeL
1Se
La
Figure 3: EDAX spectra of as-prepared Se.
measured correspond to the trigonal structure of Se withlattice constants a = 4.35 A and c = 4.93 A and are in goodagreement with those on the standard data card (JCPDS cardNo. 06–0362). Figures 1(b) and 1(c) show that the X-raydiffraction patterns of 100◦C and 200◦C annealed Se. The(100), (101), (110), (102), (111), (201), (112), (210), and(113) peaks of the 100◦C and 200◦C annealed selenium areslightly shifted when compared to the as-prepared seleniumbecause annealed samples are under a tensile strain, andthe amount of strain increases with increase in annealingtemperature. The sharpness of the diffraction peaks suggeststhat the product is well crystallized. The crystallite size ofselenium is calculated using Scherrer’s equation,
D = Kλ
β cos θ, (1)
where D is the grain size, K is a constant taken to be 0.94, λis the wavelength of the X-ray radiation, β is the full widthat half maximum, and θ is the angle of diffraction. Thecrystallite size has been calculated and is found to be in therange 30–50 nm for as-prepared, 100◦C, and 200◦C annealedselenium, respectively.
Figure 2 shows the scanning electron microscope (SEM)image of the as-prepared Se, 100◦C and 200◦C annealedselenium sample. Figure 2(a) shows the initial formation ofas-prepared selenium nanowire. Figure 2(b) shows the SEMimage of the 100◦C annealed Se nanowires. The SEM imagereveals that the Se nanowires are of uniform size with amean diameter of 30 nm. SEM image of 200◦C annealed Seis shown in Figure 2(c). It can be seen that nanowires havea length of several micrometers and diameter ranging from30 to 50 nm. It can be clearly seen that the lengths of theSe nanowires increase rapidly with increasing the annealingtemperature; however, the diameters increase slowly. There-fore, it is understood that the aspect ratios and lengthsof the Se nanowires can also be controlled by annealingtemperature. Figure 3 shows the energy dispersive X-rayanalysis (EDAX) spectra of the Se sample. In the EDAX, Se
20 nm
(a)
2.1 nm
(101)(100)
(102)(110)
(111)(201)
(b)
Figure 4: (a) Transmission electron microscope and (b) selectedarea electron diffraction images of the as-prepared Se nanowires.
is the only element detected, indicating that the sample ishighly pure.
Figure 4(a) shows the transmission electron microscope(TEM) image of as-prepared Se nanowires. The imageshows that the nanowires are straight and uniform withan average diameter of about 30 nm. Figure 4(b) showsthe selected area electron diffraction (SAED) pattern of as-prepared Se nanowires. Selected area electron diffractionimage (Figure 4(b)) exhibits diffraction rings correspondingto the (100), (101), (110), (102), (111), and (201) directionsof the trigonal phase of Se. The d-spacing values obtainedfor all the diffraction rings from the SAED pattern matchvery well with that of trigonal phase Se. Figure 5(a) showsthe TEM image of 200◦C annealed Se nanowires. The TEMimage (Figure 5(a)) confirms the formation of Se nanowireswith several micrometers of length and 50 nm diameter.
4 ISRN Nanotechnology
50 nm
(a)
2.1 nm
(101)
(100)
(102)
(110)
(111)
(201)(103)
(b)
Figure 5: (a) Transmission electron microscope and (b) selectedarea electron diffraction images of the Se nanowires annealed at200◦C.
Figure 5(b) shows the SAED pattern of 200◦C annealed Senanowires. SAED image (Figure 5(b)) exhibits diffractionrings corresponding to the (100), (101), (110), (102), (111),(201), and (103) directions of the trigonal phase of Se.The d-spacing values corresponding to plane (100) for as-prepared and annealed (200◦C) samples are found to be3.76 A and 3.73 A. The d-spacing values calculated from theseFigures (4(b) and 5(b)) are in close agreement with the valuesobtained from X-ray diffraction studies.
4. Conclusion
Selenium nanowires have been prepared by chemicalmethod. X-ray diffraction analysis reveals that the as-prepared and annealed selenium samples are of trigonalstructure. The composition analysis results show that Se ispresent in the sample. TEM images reveal that Se nanowireshave diameter ranging from 30–50 nm and length 1-2 μm.
References
[1] B. Gates, B. Mayers, B. Cattle, and Y. Xia, “Synthesis andcharacterization of uniform nanowires of trigonal selenium,”Advanced Functional Materials, vol. 12, no. 3, pp. 219–227,2002.
[2] C. R. Dillard and D. E. Goldberg, Chemistry: Reactions,Structure and Properties, The Macmillan Company, New York,NY, USA, 1971.
[3] H. Fan, Z. Wang, X. Liu, W. Zheng, F. Guo, and Y. Qian,“Controlled synthesis of trigonal selenium crystals withdifferent morphologies,” Solid State Communications, vol. 135,no. 5, pp. 319–322, 2005.
[4] B. Zhang, X. Ye, W. Dai, W. Hou, F. Zuo, and Y. Xie,“Biomolecule-assisted synthesis of single-crystalline seleniumnanowires and nanoribbons via a novel flake-cracking mech-anism,” Nanotechnology, vol. 17, no. 2, pp. 385–390, 2006.
[5] Q. Lu, F. Gao, and S. Komarneni, “Cellulose-directed growthof selenium nanobelts in solution,” Chemistry of Materials, vol.18, no. 1, pp. 159–163, 2006.
[6] X. Y. Zhang, L. H. Xu, J. Y. Dai, Y. Cai, and N. Wang, “Synthesisand characterization of single crystalline selenium nanowirearrays,” Materials Research Bulletin, vol. 41, no. 9, pp. 1729–1734, 2006.
[7] Q. Li and V. W.-W. Yam, “High-yield synthesis of seleniumnanowires in water at room temperature,” Chemical Commu-nications, no. 9, pp. 1006–1008, 2006.
[8] Y.-t. Chen, W. Zhang, Y.-q. Fan, X.-q. Xu, and Z.-x. Zhang,“Hydrothermal preparation of selenium nanorods,” MaterialsChemistry and Physics, vol. 98, no. 2-3, pp. 191–194, 2006.
[9] W. B. Zhao, J. J. Zhu, and H. Y. Chen, “Photochemicalpreparation of rectangular PbSe and CdSe nanoparticles,”Journal of Crystal Growth, vol. 252, no. 4, pp. 587–592, 2003.
[10] P. P. Hankare, P. A. Chate, D. J. Sathe, and B. V. Jadhav, “X-rayand optical properties of chemically deposited nanocrystallineCdSe thin films,” Journal of Alloys and Compounds, vol. 503,no. 1, pp. 220–223, 2010.
[11] N. Vivet, M. Morales, M. Levalois, S. Charvet, and F. Jomard,“Optimization of the structural, microstructural and opticalproperties of nanostructured Cr2+:ZnSe films deposited bymagnetron co-sputtering for mid-infrared applications,” ThinSolid Films, vol. 519, no. 1, pp. 106–110, 2010.
[12] S. Xiong, B. Xi, W. Wang et al., “The fabrication andcharacterization of single-crystalline selenium nanoneedles,”Crystal Growth and Design, vol. 6, no. 7, pp. 1711–1716, 2006.
[13] J. Di, F. Zhang, M. Zhang, and S. Bi, “Indirect voltammetricdetermination of aluminum in environmental and biologicalsamples in the presence of the aluminum chelating drugs,”Electroanalysis, vol. 16, no. 8, pp. 644–649, 2004.
[14] Y. Ma, L. Qi, W. Shen, and J. Ma, “Selective synthesis of single-crystalline selenium nanobelts and nanowires in micellarsolutions of nonionic surfactants,” Langmuir, vol. 21, no. 14,pp. 6161–6164, 2005.
[15] Q. Lu, F. Gao, and S. Komarneni, “Cellulose-directed growthof selenium nanobelts in solution,” Chemistry of Materials, vol.18, no. 1, pp. 159–163, 2006.
[16] S. Lee, S. Hong, B. Park, S. R. Paik, and S. Jung, “Agarose andgellan as morphology-directing agents for the preparation ofselenium nanowires in water,” Carbohydrate Research, vol. 344,no. 2, pp. 260–262, 2009.
[17] K. Mondal and S. K. Srivastava, “A new hydrothermal routeto nano- and microstructures of trigonal selenium exhibitingdiverse morphologies,” Materials Chemistry and Physics, vol.124, no. 1, pp. 535–540, 2010.
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